Method for catalytic conversion



Dern 17, 1946.

T. P. .:`IMFSON EVAL METHOD FOR CATALYTIG CONVERSION Filed sept. 19,1942 2 Sheets-Sheet@ Dec. l?, 1946.

fr. F'.l SIMPSON Er AL Filed Sept; 19, 1942 METHOD FOR CATALYTICCONVERSION Sheets-Sheet 2 NVENTOR BY ATTORNEY Patented Dec. 17, 1946 ,yMETHOD FOR CATALYTIC CONVERSION Thomas'P. Simpson, `John W. Payne, andJohn A. Crowley, Jr., Woodbury, N. J., assign Socony-Vacuum Oil Company,Incorporated, a. corporation of New York i Application September 19,1942, Serial No. 458,926

(ci. 19e- 52) n A 14 Claims.

. A l f Y 'I'his invention is directed to mass, such as, for example,the catalytic conversion of hydrocarbons. Y

It is known that many operations for the conversion of hydrocarbonmaterials to other hydrocarbon materials of differing -physical and/ormethods of conducting reactions in the presence oi.' a contact lCIIchemical properties may be carried out catalytically. Most of these arecarried out by contacting the hydrocarbon, usually in vapor form and athigh temperature, with a contact mass composed of particles whichthemselves have a catalytic eilect, or which are impregnated with or actas a support ior other catalytic material of a nature appropriate to theresult desired. Such operations may contemplate, for example, theconversion of hydrocarbons of high boiling point -to those of lowerboiling point, or the polymerization of light or gaseous hydrocarbons tohydrocarbons of higher boiling point. Other operations of like natureare catalytic dehydrogenation, hydrogenation, desulphurizing, partialoxidation and similar conversions of hydrocarbon materials. The methodot operation herein disclosed is applicable to all such conversions. Ofthese operations, the vapor phase cracking of heavy hydrocarbons togasoline is typical, and

this specification will hereinafter discuss such 4operation asexemplary, without, however, intending to be limited thereby or theretoexcept by such limits as may appear in the claims.

Such catalytic processesgenerally make use of -reactlon chamberscontaining a fixed body of catalyst or contact mass, through which thereaction mixture is passed, and in which, after the reaction has sloweddown to an uneconomic point, the contact mass is regenerated in situ.Such .processes are not continuous, andv only attain continuity by theprovision of numerous reaction chambers which arev alternately placed onstream and on regeneration. Likewise, it is difiicult to maintainconstant quantity and quality of product withoutnumerous chambers andintricate scheduling, due to the progressively decreasing activity ofcatalyst.' This same feature, with apparatus limitations,` prevents, ltoa degree, the

use of catalyst at a uniform high eillciency level. Mostv of thesedifculties may be avoided bythe use of a method wherein the catalyst orcontact mass is handled continuously as well. This invention isvspeciically directed to'such a process.

This invention has for its object the provision of a process ofhydrocarbon oil conversion wherein a continuously moving stream ofhydrocarbon oil is contacted with a continuously moving 2 stream oi.'catalyst for the accomplishment of conversion, in which the catalyticmaterial is used only at a high level of eillciency, and in which thecatalytic material is continuously regenerated and returned to theconversion step, both operations being conducted under controlledconditions.

This invention has for a major object the establishment of propercontrol factors for the eillcient operation of such a process.

This invention is based. upon the principle ot carrying out -catalytlcreactions by flowing a stream4l oi reaction mixture in physical contactwith a ilowing stream of catalytic material.

In order that this invention may be understood, reference is made to thedrawings attached to and made a part of this specification. In thesedrawings, Figure 1 shows in diagram form a reaction and regenerationapparatus suitable for use in this process, Figures 2, 3,4, 5 and 6 areconcerned with internal details of such cham# vergent bottomvii, andltted with an interiorfalse bottom I5, which is perforate, theperforations therein being too small for the passage of catalystparticles but permitting the passage of liquid or gas.- Bottom Il isitted ywith pipe I6, and top I3 with pipe Il. At the top of I3 is asealed feeding device I8, which may be a star wheel as shown, anintermittently operated valve set-up or other common' device of thisnature'. Catalyst material introduced through I8 lls the interior ofshell 8, passes down therethrough, 'is collected by false bottom' I5 andchuterIB- and is removed by a second intermittentlyoperating device,such as star wheel 20.4 Thisarrangement effects a continuously movingstream of catalytic material through shell 8. Reaction mixture, in thiscase air for an oxidizing regeneration, may be introduced through pipeI6 and products oi reaction, in this case flue gas, may be removedthrough pipe Il. This effects a continuously flowing stream of reactionmaterial in physical contact with the continuously flowing stream of 3catalytic material in shell 8. 'I'he flow shown is countercurrent. Ifdesired, it may be made concurrent by reversing the func\tlonslof I8 andI1. Shell 8 is also internally iitted with a series of conduits 2l,equipped with ns 22,l joined to headers 23 and 24, through which a heatexchange medium may be passed by-means oi pipes l 25 and 25. The/liestexchange medium may be used to control the temperature of reaction byextraction of heat from or addition of heat to the material within shell8, and its ow may be concurrent, countercurrent, or, as later shown,

In certain reactions, no heat transfer elements are required in thereaction chamber.

Figure 2 shows a cross-section oi case 8 at the level 2-2 showing howthe preferred longitudinal passages may be formed by equipping each heatexchange tube with two diametrically opposed, longitudinally disposedaxial fins. Figures 3 and 4 show other ways of arriving at the sameresult. The heat transfer tubes need not be arranged parallel to theflow of catalyst, but may well be transverse thereto, as shown inFigures 5 and 6, wherein transverse tubes 39, carrying ilns.40, extendbetween header boxes 4I and A 42 in a shell 43, to exercise the samefunctions as steam may be passed throughthe catalyst for purging. Asimilar purging passage I I lies below shell I0, is controlled bydevices and 35, and itted with steam pipes 36 and 31 for purgingcatalyst after reaction.` From `II the catalyst drops through intoboot\38 of elevator I2 by which it is elevated and discharged into bin38a above shell 8. Elevator I2 may be of the belt and bucket type shownor of any other kind suitable for the physical properties of thecatalytic materials. It will be seen that in apparatus of the type shownin Figure 1 there is a controlled gravity flow of catalyst throughshells 8 and ID into the feed boot 38 of the elevator I2 which returnsspent catalyst to the inlet of shell I 0, thereby providing means forcarrying out the continuous catalytic process contemplated herein withSpecial attention should be given to the arranged ment of heat exchangetubes within the shells 8 and I0. These should be so arranged as topromote the passage of catalytic material and reaction materiallongitudinally through the shell in such manner that the owing materialis at al1 times in heat exchange relationship with the heat exchangemedium whilein the zone of heat exchange elements. It will be seen fromFigure 1, regenerator 8, that a zone above. and a zone below the heatexchange tubes provide space in ywhich the temperature is independent ofcontrol other than temperature of reactants and nature of the reactionstaking piace. The conduits may be unnned, but better results areobtained if the external heat transfer surface of the heat exchangetubes is augmented by the addition of fins thereto.v These fins,primarily added for heat transfer reasons may be taken advantage of toassist in control of the flow of catalyst and reaction fluid and contacttherebetween by being disposed so that they, together with the tubes,divide the space within the shell into a series of longitudinal passagesof substantially constant cross-section throughout their length.

corresponding parts in shells 8 and IIJ.

It will also be noted in Figures 5 and 6 that the heat exchange elements39-40 may be spaced apart -so as to provide within the regenerationchamber severalzones intermediate of its ends. wherein combustion maytake place without substantial simultaneous removal of heat.

The heat exchange medium, if used, may be any iluid suitable for theload and temperature levels encountered, such as gases, liquids ofvarious kinds, molten metals, or alloys, or fused salts. Preferably itshould be possessed of a low vapor pressure, low viscosity, and highspecic heat at operating temperatures and non-corrosive to steel.

Passages 8 and II, used for purging by passing steam through thecatalyst particles, should be so proportioned that a suillcient contactof steam and catalyst particles occurs to remove the residual volatileproducts of the preceding reaction.

'Inrnlng to Figure 7, which shows an operating setup appropriate for aconversion of hydrocarbons, such as, for example, a vapor phasecracking, we find charge oil fed through pipe 44 by pump 45 to a vaporpreparation unit` 46. Vapor preparation unit 46 vwill consistessentially of a heater, for which purpose any of the usual forms ofheater common in the art, say a pipe still, may be used, to heat andvaporize the charge and heat it to reaction temperature, and, if thecharge used is not wholly vaporized at the reaction temperature, a vaporseparator to remove unvaporized liquid'residue. Vapors from 46 movethrough pipe 41 into and through reaction chamber 48 (the same as I0,Figure 1), and therein undergo catalyticA reaction. Reaction productspass through pipe 49 .to product purication and recovery equipmentdenoted by 50. 50 may be made up of any of the usual fractionation,separation and disposal devices currently in common usel for handlingproducts of cracking reactions@ If desired, product fractions boilingabove theV desired low-boiling product may be returned to the systemforretreatment, either separately or in admixture with fresh charge.Catalytic material ilowing from 48 is purged in 5I and elevated by 52 tobe introduced into 53 Jwherein it is regenerated by burning with airsupplied by blower and pipe 54, the products of regeneration beingdisposed' of through pipe 55, after which the regenerated catalyst ispurged in 551and returned to 48. The temperature level of the reactionin 48 may be controlled and latent heat of reaction added thereto by aheat exchange medium introduced through pipe 51 and removed through pipe58. In the arrangement shown in Figure rI the same heat exchange mediumused in 48 may also be used to control the temperature of regenerationin 53. In the oper- .ation described herein, where the regeneration isan exothermlc reaction, the function of the heat Y Yield or dry gas(lighter-, than isobutane) VYield of corel Yield 'of recycle stock.'

- exchange :mediumrinthe 'intermediate region of ature of the movingmass in the intermediate region thereof, between a minimum temperaturebelow which burning of the carbonaceous deposit in the presence ofoxidizing gases at an appresiable rate cannot occur and almaximumtemperature above which the catalytic material would be damaged by heat.For example, the temperature for regeneration of a spent clay typecatalyst used. in cracking hydrocarbons may range from around the.cracking temperature (from about 800 to about 950 F.) to apealctemperature in the neighborhood of 1050 to-1100 F.- Care should beexercised so that the regenerating temperature does not risesubstantially above i200v F. or serious damage to a catalyst of thistype may result.-1'n.the arrangement shown in Figure '1, the heatexchange medium is introduced into 53 by pipe 69 and removed by pipe 60;The heat exchange medium is circulated by e catalyst, no detectabledeterioration in quality` being found.

The control of several features of the operation is oi considerableimportance. In both the regenerator and reactor, the particle-form solidcatalyst is moved down through the operation in the form of a solidmoving. column while the reactants (oxidizing gas in one case andhydrocarbons in. the other), are passed countercurrently therethrough.In order to c ifectively secure. contact of the reactants with allportions of the contact mass it is necessary that the reactants bepassed therethrough at such velocity that the orderly and uniformprogress of the contact mass is not impeded, and that channels whereinreactants might pass through rapidly without adequate 'reaction beprevented from forming. It has been determined that the preipump Siandthe temperature for the several uses may be controlled by use ofvarious combinations of heat exchangers 82 and 83 and bypasses 64, $5and 86 in a manner obvious to those skilled in the art. In many cases ifthe reactions taking place in chamber I8 have a relatively small heat ofreaction or where maintenance of closely controlled temperatures is notessential it is unnecessary to circulate the heat transfer mediumthrough the chamber. and a satisfactory heat balance and temperaturescan be attained by balancing the temperatures of the entering re actantsand catalyst,... a

As an example of one operation successfully conducted in such apparatus.according to the process herein disclosed, coastal gas oil with whichwas admixed steam to the extent of about `'ioogl (cold volumes), at atemperature of 800 F. was contacted with a catalyst of activated claygranules at a rate of one volume of oil (cold) to tour volumes of clayin a chamber through which the clay passed at such a rate that itremained in the reaction zone about 20 minutes... with the followingresultsz;...gy4v u vi 1.

Yield 'ofno" E. P essonne (including isobutane and heavier in gas) vol.per cent-- 67.4

wt. per cent 4.0 ..-wt. per cent-- 2.5 voL per cent-.. 35.0

In this runthe catalyst was passed through the regeneration chamber (ofthe same size as the reaction chamber) at the same rateand was burnedwith a suillcient volume of air to maintain above 10% CO: in the exitflue gas.

The temperature of the reaction was held by use of the heat exchangemedium at 800 F., and in the same manner the temperature of theregeneration was not allowed to rise above 1100 F.

The gasoline produced was of excellent quality, high in anti-knockrating, and the recycle stock was clean. light in color, and of aboutthe same boiling range as the charge. No high boiling, dirty, liquidcracking tar was produced. The regenerated catalyst was equal inelciency to new erable upper limit for reactant velocity is somewhatbelow that at which active physical disturbance or "boillng of thecontact mass will occur. Of course, since various reactants may be used.of varying densities and varying viscosities at the temperature ofreaction, ranging from air to relatively heavy hydrocarbon, the actuallinear velocities will vary for each reactant. Also, for particles ofvarious sizes, the resistance of a given depth ,of bed isgreater in somecases, giving rise to another variation in the actual linear velocity ofthe reactant.. However, it has been determined that all of thesevariables merge in auch a manner that it can be stated that the maximumflow of any reactant, through any particle form solid catalyst of claytype, should not be greater than that which will produce a pressure dropof about 6 inches of water per foot of path through the contact mass,measured between the most nearly adjacent points of inlet and exit.

This limiting value of pressure drop will vary with the apparent densityof the contact mass material in the solid moving column. That is,

Vfor contact mass materials which have a greater' weight per unit ofvolume in the state of packing density of 1.1. Since fuller's earth,"uitrol," acidtreated natural clays. and most synthetic ma- A terialsnow in use and of this general type have apparent densities ranging fromabout 0.6 to 0.8 a pressure drop of about 6" to 8" of water-per terialsof clay type. vHowever, other 'catalytic materials which are also usefulwill include materials of higher apparent density, such as certainsynthetic associations of alumina and silica, or may include materialsof the clay-type. or of synthetic origin carrying a suilicient amount ofother catalyst, such as certain well known catalytic metals carried byclay type carriers. With these, the upper limits of optimum pressuredrop are indicated.

The limits so far discussed are optimum and preferred limits, as will beunderstood from the following. Obviously. greater economic usefulnessresults from greater use of each unito! reaction space installed. thatis from greater thruputof reactant per cubic foot of installed contactmass volume. Also, particularly in cra;k ing of hydrocarbons, thelaydowh of carbonaceous matter'on the contact mass does not increaserproportionately vwith increases in reactant thruput per unit volume o!contact mass. Reaction can, of course, be attained above these preferredlimits, up to rates of reactant thruput which are sults may be obtainedto an operable degree by burning olf, in each such combustiveregeneration stage without substantial removal of heat, from about 0.05per cent to about '0.60 per cent by weight of coke, based on contactmass weight.

The controls herein set forth cooperate to permit the establishment of ahighly useful cyclic water pressure drop per foot of path through 1 thecontact mass and preferably not greater than one giving about 6 to 8inches of water pressure drop per foot of path through the contact mass.

For the heavier contact mass materials the optimum pressure drop willrange upward to about 11 inches oi' water per foot of path, with themaximum pressure drop ranging upwardly to about 13 inches of water perfoot of path.-

. f similar interest and importance is the control of burning in theregenerator, particularly in those portions of the regenerator whereburning may take place without simultaneous removal of heat. Therequired temperature limits for combustive regeneration are, as aminimum, the temperature whichv will support combustion, namely about'150 F. as a practical minimum and 800 F. as a preferred minimumtemperature level in regeneration. The maximum is that temperature atwhich the contact mass will be damaged or reduced in eiiiciency by heat.As a matter of practical operation, the operating maximum will be about950 F. to about 1100 F., with 1200A F. set as an operating maximum whichshould not be exceeded.

In order to attain the control necessary to avoid these maximumtemperatures and at the same time assure complete control ofcarbonaceous deposit, the operation should preferably be varied inaccordance with .the amount of irnpurity, usually spoken of as coke Ifthe coke to be burned oi! is large in amount, say above about 3 per centby weight of the contact mass,

- the exothermic heat generated by its burning is so great relative tothe heat capacity of the catalyst and combustion' gases that a generallysimultaneous burning andremoval of heat is advantageous. If the coke tobe removed is below about 3 per cent and particularly if it is below 1per cent by weight of the contact mass, a consid- `erably better burn onor regeneration may be obtained by permitting periods of burning withoutsubstantial simultaneous removal of heat in order to permit of morecleanly removing dinicultly ignitable coke. These conditions ofrelatively small coke burnoii! are typical of the regeneration ofcontact mass material spent in cracking, and for this reason, whenworking with such a .process it ispreferred to use a regenerator Aequipped as shown in Figures-5 and 6 where regions of burning withoutsubstantial simultane: ous removal of heat are alternatedwith heatremoval regions. However, control of maximum temperature is necessary inthese combustion regions without heat removal means and this can beprovided by so adjusting the intensity of com-l commercial process. Thecontrol set forth for the conversion reaction accomplishes high rates ofconverted product production per unit of catalyst volume employed, whileat the same time permitting relatively low rates of coke deposition. Forthis optimum conversion operation, it is .highly desirable to provide acatalytic contact mass of controlled activity. The regeneration controlset forth permits of attaining such controlled regeneration of spentcatalysts in proportion .to

the amount of coke deposited thereon.

It is to be understood that the specific examples and numerical dataherein disclosed are explanatory of the invention, and that it is not tobe limited thereby or thereto except as such limitations are expressedin the claims.

This application is a continuation-impart of our copending applicationSerial No. 361,440, filed October 16, 1940, which, in turn, is acontinuationin-part of our application Serial No. 162,541, filedSeptember 4, 1937.

We claim:

1.l The method of converting a hydrocarbon oil which comprises passingthe oil in vapor phase contaminant therefrom and removing heat sufcientto prevent the temperature of regenerating contact mass from risingabove .that which will damage the contact mass` and returning theregenerated contact mass in heated condition to the conversion zone. A

2. The method of converting a hydrocarbon oil which comprises passingthe oil in vapor phase and at conversion temperature into contact with asubstantially compact, upright column of gravi- .tating particle-form,clay-type, solid catalytic material in which conversion is effected, thevapors being introduced thereto at a iiow rate not in excess of sufcientto produce about six =to eight `inches of water pressure drop per footof vapor path through said column, effecting substantially completeseparation of hydrocarbons from said column, transferring contaminatedcatalytic material to a regeneration zone and moving it therethrough asa substantially compact column of moving particles, supplying oxygencontaining gas thereto to burn contaminant therefrom and positivelyremoving heat sufiiclent to prevent the temperature of regeneratingcatalytic material from rising above that which will damage thecatalytic material, and returning the regenerated contact mass in heatedcondition to the conversion zone.

3. The method of converting a. hydrocarbon oil which comprises passingthe oil in vapor phase and at conversion temperature into contact withvapors being introduced thereto at a iiow rate substantiallybelowthatwhich causes physical anaal? disturbance of themovingmass,eiectlng sub- 4 stantially Icompleteiseparation 'of hydrocarbons fromsaid mass. transferring contaminated contact mass to a regeneration zoneand moving it therethrough as a substantially compact downwardly movingmass'. supplying omgen containing gas thereto to burn contaminanttherefrom, said'gas being supplied at a flow rate not in excess ofsuilicient to produce about seven to ten inches of water pressure dropper foot of gas path through said mass, and removing heat suiilcient tokprevent the temperature of regenerating contact mass from rising abovethat which will damage the .contact mass, and returning the regeneratedcontact mass in heated con- 'dition to the conversion acuer,A :1, 'A

4. The method of converting a hydrocarbon oil which comprises passingthe oil ln vapor phase and at conversion temperature into contact with asubstantially compact downwardly moving mass of particle-form solidcatalytic materialof clay type in which conversion is eilected, thevapors being introduced thereto at a flow rate substantially below thatwhich causes physical disturbance of the moving mass. effectingsubstantially .complete separation of hydrocarbons from said mass,transferring contaminated contact mass to a regeneration zone and movingit downwardly therethrough as a substantially compact movins Supplyingengen containing gas thereto to burn contaminant therefrom, said gasbeing supplied at a ilow rate not in excess of suiliclent to Aproduceabout six to eight inches of water pressureI drop per foot of gas paththrough said mass, while removing heat sufficient to prevent thetemperature of regenerating contact mass from rising above' that whichwill .damage the contact mass. and returning the tating particle-formsolid catalytic material of clay type in which conversion is effected,the vapors being introduced thereto at a flow rate substantially belowthat which causes turbulence tinuously passing said material as asubstantially compact column through Aa plurality of zones in whichcombustion occurs without substantial simultaneous removal of heat, saidcombustion zones alternating with cooling zones in whichv heat isremoved by indirect heat exchange with a iluid heat exchange medium, thetemperature at all times being maintained between a.'

minimumtemperature at which combustion will take place and a maximumtemperature at which the catalytic material begins to suffer heatdamage, the amount of burning in each combustion zone being limited tothe burning ofi ci from 0.05 percent to about 0.60 per cnt by weight ofcarbonaceous material based on catalytic material weight.

7. The method of regenerating a particle form solid, clay-type,catalytic material contaminated by a carbonaceous deposit whichcomprises continuously passing said material as a substantially compactcolumn through a plurality of zones in which combustion occurs withoutsubstantial simultaneous removal ofheat, said combustion zonesalternating with cooling zones in which heat is removed by indirect heatexchange with a uid heat exchange medium, the temperature at all timesbeing maintained between a minimum temperature at which combustion willtake place and a wmaximum temperature at which the catof the movingmass, effecting substantially com` plete separatlonof hydrocarbons fromsaid mass;

'transferrlng':;contaminated' contact mass to a regeneration'zone andmoving it therethrough as a substantially compact downwardly movingvmasssupplying oxygen containing gas thereto f to burn' contaminanttherefrom, said gas being supplied 'at a'ilow ratesubstantiallyvbelowthat which causes turbulence of the moving mass, and removing heatsumcient to prevent the temperature of regenerating contact mass fromrising above that which will damage the contact mass,

- t and returning the regenerated contact mass in heated Vcondition tothe conversion zone, the ilow rateol vapors ln the conversion sectionand 6.2 The method of regenerating a particle form solid, clay'type,catalytic material contaminated by a carbonaceous deposit whichcomprises conalytic material begins to suier heat damage, the amount ofburning in each combustion zone being limited to the burning oi of 0.60per cent by weight of carbonaceous material based on catalytic materialweight.

8. The method of regenerating a. particle form clay type solid adsorbentmaterial contaminated by acarbonaceous deposit which comprisescontinuously passing said material as a substantially compact columnthrough a plurality of. zones in which combustion occurs withoutsubstantial rsimultaneous removal of heat. said combusticn zonesalternating with cooling zones in which heat is removed by indirect heatexchange with a fluid heat exchange medium, the temperature at-all timesbeing maintained betweenv per cent by weight of carbonaceous materialbased on adsorbent material weight and the flow rate of regenerationgases therethrough being not over sufficient to produce a pressure dropof about i? seven to ten inches of water'per footof gasifpath throughsaid material.

9. The method of regenerating a particle form clay type solid adsorbentmaterial contaminated by a carbonaceous deposit which comprises con.- '5tinuously passing said material as a substantially compact columnthrough a plurality of zones in which combustion occurs withoutsubstantial simultaneous removal of heat, said combustion zonesalternating with cooling zones in which heat is removed by indirect heatexchangel with a iluid heat exchange medium, the temperature at alltimes being maintained between a minimum temperature at which combustionwill take placeKY and a maximum temperature at which the adsorbentmaterial begins to suier heat damage, the amount of burning in eachcombustion zone being limited to the burning oi of 0.60 per cent byweight of carbonaceous material based'pn adsorbent material weight andthe flow rate oi regeneration gases therethrough being not oversufilcient to produce a pressure drop of six to eight inches of waterper toot of gas path through said material. f

10. The method of converting a hydrocarbon oil which comprises passingthe oil in vapor phase and at conversion temperature into contact withing accomplished by passing said material as a substantially compactcolumn through a plurality" of zones in which combustion occurs withoutsubstantial simultaneous removal of heat, said comf bustion zonesalternating with cooling zones inv which heat is removedby indirect heatexchange with a fluid heat exchange medium, the temperaweight ofcarbonaceous material based on cata-V lytic material weight, andreturning the regener vertedfproducts made per unit volume of catalystemployed and still at an amount not suilicient to produce a pressuredrop in excess of about seven toten inches of water per foot of path fvapors through said material, flowing the relay tively low contaminantcontent contact mass material therefrom into'ard through a regenerationa zone in' which 'said material flows" as a substantiallyeompact movingcolumn and ismaintained at al1 times at a temperature high enough tosup-f port combustion and below a'temperature high enough to eilect heatdamage to said material,

'burning contaminant from said material in a plurality of regenerativesteps in each of which no more than about 0.05 per cent to 0.60 per centby weight of contaminant, based on contact mass weight. is removed fromsaid material and in each ated catalytic 'material in heated conditioninto contact with oil vapor. f

duced thereto at a ow rate substantially below` that which causesturbulence of the moving mass,

eilecting substantially complete separation of hydrocarbons fromV saidmass-transferring contaminated contact mass to a regeneration zone,supplying oxygen containing gas thereto to burn contaminant therefrom,said burning being accomplished by passing said material as asubstantially compact column throughs plurality-of zones inwhich'combustion occurs without substantial simultaneous removal ofheat, said combustion zones alternating with cooling zones in which heatis removed by indirect heat exchangey with a iiuid heat exchange medium,the temperature at all times being maintained between a minimumtemperature at which combustion will take place and a maximumtemperature at which the catalytic material begins tosuffer lheatdamage. the amount of burning in each combustionf zone being limited tothe burning off of 060 per cent by weight of carbonaceous material basedon catalytic material weight and returning the regenerated contact massin heated condition into contact with oil vapor. i 12. A unitary processfor conversion of heavy hydrocarbons to lighter hydrocarbons in thepresence of a catalytic contact mass of particle form, clay type. solidadsorptive material comprising the steps of ilowing the contact massmaterial as a substantially compact moving column through a reactionzone, flowing a stream of hydrocarbons heated to conversion temperaturestherethrough of which no substantial removal ofvheat is effected.between said burning zones removing heat t from said material byindirect heat exchange with a iiuid heat exchange medium, the iiow rateof regeneration gases being high to effect good penetration of saidmaterial but not suilicient to produce a pressure drop in excess ofabout seven to ten inches of water per foot lof path of gas throughsaid'material and returning the regenerated contact mass in heatedcondition to the reaction zone.

13. A unitary process for conversion of heavy hydrocarbons to lighterhydrocarbons in the presence of a catalytic contact mass oi particleform, clay type, solid adsorptive material comprising the steps of owingthe contact mass material as a substantially compact moving columnthrough a reactionzone, flowing a stream of hydrocarbons heated toconversion temperatures therethrough at a high flow rate conducive torelatively low deposits of contaminant on catalyst relative to con.

' verted products made per unit volume of catalyst employed and still atan amount not suicient to produce a pressure drop in excess of about sixto eight inches of water per ioot of path of vapors l. through saidmaterial, ilowing the relatively low Y contaminant content contact massmaterial 0.60 per cent by weight of contaminant, based at a high flowrate conducive to relatively low deposits of contaminant on catalystrelative to conon contact mass weight, is removed from said material andin each of which no substantial removal of heat is effected, betweensaid burning zones removingpheat from said material by. indirect heat`exchange with a fluid heat exchange medium, the ow rate of regenerationgases being high to eiect good penetration of said material but notsuilcient to produce a pressure drop in excess of about six to eightinches of water per foot of path of gas through said material andreturning the regenerated contact mass in heated condition to thereaction zone.

14.The method Aof converting a hydrocarbon oil which comprises passingthe oil in vapor.

n seven 'to thirteen inches of water per foot of path of vapor throughcontact mass for contact mass materials of` apparent densities in thereactor ranging from about 0.6 to about 1.1, the pressure drop,\withinthe indicated range being proportional to the said apparent density,effecting Vsubstantially complete separation ofhydrocarbons from saidmass, transferring contaminated contact mass to a regeneration zone andmoving it therethrough as asubstantialiy compact moving mass, supplyingoxygen' containing gas thereto to burn contaminant therefrom andreturning -the regenerated contact mass in heated condition to theconversion zone.

v THOMAS P. SIMPSON. JOHN W. PAYNE. JOHN A. CROWLEY, JR.

